Integrating locomotion, postures and morphology: The case of the tayra, Eira barbara (Carnivora, Mustelidae)

Locomotion and postures are key factors to understanding the biology of animals. However, scansorial and arboreal carnivorans remain poorly studied regarding these issues. Herein, we present a behavioral and morphological analysis of the arboreal locomotion of the tayra (Eira barbara), a neotropical forest-dwelling mustelid. Data on habitat use and locomotor and postural modes were collected from free-ranging tayras in a terra-firme forest in French Guiana. Additionally, qualitative morphological traits and linear measurements of the girdles and appendicular skeleton were analyzed through comparative anatomical descriptions, univariate tests, and a principal components and discriminant analysis. Tayras frequently used clambering, quadrupedal walking, claw climbing and quadrupedal standing, performed primarily on small and medium, oblique and horizontal branches. Furthermore, our morpho-functional analyses revealed that tayras possess autopodial specializations for navigating on arboreal substrates, while the more proximal elements present features more similar to other terrestrial or scansorial mustelids, and theoretically less modified from the hypothetical weasel-like ancestor of mustelids. This mosaic of morphological features of the tayra, a combination of phylogenetic inertia and ecological signals, very likely evolved to promote the efficient and effective exploitation of diverse habitats and resources in this versatile species.